In conventional tape measures, a pressing means was provided at a side of the tape measure body, and the stopping of the rule is carried out by pressing a pressing means directly onto the rule.
Therefore, after a repeated long term use of a tape measure, the contacting top of the pressing means was rubbed off, resulting in the rule failing to stop at the intended position, and slipped off, when the pressing means was pressed. Further, after the stopping of the rule, if the rule is pulled out with a slight force, the rule is easily and continuously slipped out, making it difficult to expect a sure stopping effect.
Another disadvantage of conventional tape measures was that, if the device was repeatedly used, the scale marks on the rule were easily erased due to the frictional contact between the upper face of the rule and the pressing means. Such devices are shown, for example, in U.S. Pat. Nos. 3,578,259; 3,214,836; 3,435,529; 2,536,766; 3,041,044 and 2,288,923.
The coilable rule locking mechanism of U.S. Pat. No. 3,578,259 has a locking mechanism wherein an actuator at the front of the casing can be simply pivoted to actuate a vertically reciprocable lock member which, when moved to Clamping position, securely and reliably holds the tapeline in a particular position of extension from the tape casing. The locking mechanism is operable to clamp the tapeline against a resilient pad.
The coilable rule of U.S. Pat. No. 3,214,836 has a locking mechanism comprising an arcuate slide molded from a suitable flexible, resilient, hardwearing and self-lubricating material such as nylon.
The linear measuring instrument of U.S. Pat. No. 3,435,529 has in a linear measuring instrument casing, a single pivoted lever that locks the tape against an inner wall of the casing.
The locking device for flexible tapes of U.S. Pat. No. 2,536,766 has a locking device for the tape that locks the tape when extended and the measurement is made, thereby preventing any slippage of the tape when the tape is moved to a convenient position for reading and an accurate reading is assured.
As shown in the measuring tape of U.S. Pat. No. 3,04,004, the tape rule is of the type wherein the measuring tape can be withdrawn from the case any selected distance and held there by a brake mechanism. After a measurement is made the tape can be automatically pulled back into the case by means of a spring motor inside the case.
The tape measure of U.S. Pat. No. 4,288,928 has a pivot pin for pivotally mounting a braking lever to the housing for locking the tape in a desired extension position in which a shock absorbing element of a deformable, resilient material is associated with the pivot pin for absorbing shock from the hook member during the return of the tape to its retracted position. The tape measure has a coiled measuring tape adapted to be locked in an extended or unwound position.
As shown in the above-listed U.S. patents, the present invention does not use the structures of the above listed patents and the invention has no features of the above listed patents.